Auto show dream cars with glass doors never quite seem to graduate to reality; aside from that, a more conventional body is all that could keep this dream from becoming a latter-day M1.

What makes it tick? The Vision is a plug-in hybrid with a 1.5-liter diesel engine and two electric motors. Total output is 356 horsepower, and peak torque is a body-slamming 590 pound-feet. Acceleration to 60 m.p.h. takes just 4.8 seconds, and the top speed is said to be 155. Average fuel consumption is 62.6 m.p.g., BMW says. The car has an electric-only range of 31 miles; but it is theoretically capable of more than 400 miles in combination with the fuel in its 6.6-gallon tank.